Table 6.

Quality Assessment of included cohort studies on

Study	Score	Representativeness of exposed group	Selection of non-exposed cohort	Ascertainment of exposure	Demonstration that outcome of interest was not present at the start of the study	Comparability of cohorts on the basis of the design or analysis	Assessment of outcome	Was follow-up long enough for outcomes to occur?	Adequacy of follow up of cohorts
Kilani,2015	8	*	*	*	*	*	*	*	*